[EliRivers]

I'd want to be able to split it horizontally and vertically, and sub-split those similarly, ad infinitum (see eMacs C-x 2 and C-x 3), cycling through them with convenient copy/paste across them, with them also aware of each other and able to pipe information to each other.

There are some that split to various degrees already; I don;t know how aware the panes are of each other or if they'll happily pipe into each other. I'd like to be able to run a script in one pane and have the outputs go into different panes as directed by the script.